using ArcGIS tools or other software.
Figure 2.9 An example of a data clip as illustrated in ArcGIS documentation. The dataset on the left covers an area larger than needed. The study boundary (center) is used as a “cookie cutter” to clip the data down to the study region. Esri Resources: Clip (Analysis).
The idea behind thinking through your logic, independent of the software to be used, is to avoid one of the most common pitfalls in GIS analysis: allowing the software, or your knowledge of particular tools, to dictate how you analyze your data. After developing your logical data model, you might have a good basis for selecting the most appropriate GIS software and add-ons (potentially including some new extensions or add-ons) for your analysis. This is akin to every problem looking like a nail when you are only familiar with a hammer. If, in fact, logic dictates using a screw, then obtain and learn to use a screwdriver.
Of course, you can’t completely change software tools for each new analysis. Once your organization has committed to a particular program, you need to take advantage of what it offers, perhaps adding individual extensions or additional tools as needed. Most software, such as ArcGIS, includes thousands of tools and options, more than the typical user can keep track of. So, even if you are not sure how to implement your logical model when you develop it, there is usually room to explore options you may not have considered to determine the best approach to analyzing your data following the logic developed at this step of the abstraction process.
AN ASIDE ON CHOOSING THE RIGHT TOOLS FOR YOUR ANALYSIS
Selecting the right tools for your analysis is essential to conducting research in GIS. It is important to avoid tunnel vision when it comes to the software you incorporate into your analysis. The value of the logical data model is that you think through what you want to accomplish without being distracted by the question of how you will accomplish this from a software perspective. Once you have worked out the logic model, or what you wish to accomplish in your analysis, you can turn to how you can best accomplish it with the physical model.
Selecting the physical tools for the job may require you to go beyond the software tools you already know. Although GIS software packages, such as ArcGIS, provide a relatively complete, out-of-the-box solution, it is not unusual for additional software tools to be required to carry out your analysis.
ArcGIS is compatible with optional software components, called extensions and add-ons, that enhance its capabilities for a particular type of analysis (table 2.1). Extensions and add-ons come in three primary varieties: Esri-developed add-ons, third-party add-ons, and user-contributed add-ons. Although these products can sometimes be expensive, they can pay for themselves in time and effort saved on routine or repetitive analysis tasks. A substantial number of freely available extensions and add-ons are also available. Finally, a wide array of stand-alone software tools (both commercial and free) may be used in conjunction with ArcGIS.
Table 2.1 Extensions and add-ons available from Esri
| Extension/add-on | Key benefits |
| Analysis | |
| ArcGIS 3D Analyst | Analyze your data in a realistic perspective. |
| ArcGIS Geostatistical Analyst | Use advanced statistical tools to investigate your data. |
| ArcGIS Network Analyst | Perform sophisticated routing, closest facility, and service area analysis. |
| ArcGIS Schematics | Represent and understand your networks to shorten decision cycles. |
| ArcGIS Spatial Analyst | Derive answers from your data using advanced spatial analysis. |
| ArcGIS Tracking Analyst | Reveal and analyze time-based patterns and trends in your data. |
| Business Analyst Online Reports | Directly access demographic reports and data from Business Analyst Online (BAO) for trade areas and sites created in the desktop. |
| Productivity | |
| ArcGIS Data Interoperability | Eliminate barriers to data use and distribution. |
| ArcGIS Data Reviewer | Automate, simplify, and improve data quality control management. |
| ArcGIS Publisher | Freely share your maps and data with a wide range of users. |
| ArcGIS Workflow Manager | Better manage GIS tasks and resources. |
| ArcScan for ArcGIS (included with ArcInfo and ArcEditor 9.1 and higher) | Increase efficiency and speed up raster-to-vector data conversion time. |
| Maplex for ArcGIS (included with ArcInfo 9.1 and higher) | Create maps that communicate more clearly with automatically positioned text and labels. |
| Solution-based | |
| ArcGIS Defense Solutions (includes ArcGIS Military Analyst, Grid Manager, and MOLE) | Create workflows, processes, and symbology to support defense and intelligence planning. |
| Esri Aeronautical Solution | Use the full power of GIS to efficiently manage aeronautical information. |
| Esri Defense Mapping | Efficiently manage defense specification-compliant products. |
| Esri Nautical Solution | A GIS-based platform for nautical data and chart production. |
| Esri Production Mapping | Standardize and optimize your GIS production. |
| No-cost add-ons | |
| ArcGIS Editor for OpenStreetMap (download) | Contribute to the OpenStreetMap project by adding, editing, and deleting data within the familiar ArcGIS 10 editing environment. |
| ArcSketch (download) | Quickly create features in ArcGIS with easy-to-use sketch tools. |
| Districting for ArcGIS (download) | Create defined groupings of geographic data, such as census tracts, ZIP Codes, and precincts, by creating a districting plan. |
| Free Geoportal add-ons (download) | Catalog geospatial resources within an enterprise and provide quick access to those resources regardless of location or type. |
| Geodatabase Toolset (GDBT) (download) | Manage your scalable geodatabases with diagnostic performance tools. |
| OLAP for ArcGIS (download) |
Create, view, use, and manage connections to OLAP databases in ArcGIS
|